Method and apparatus for driver circuit

• US 20060176746A1
• Filed: 02/08/2005
• Published: 08/10/2006
• Est. Priority Date: 02/08/2005
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Martin, Eric, Wang, Stanley J., Enciso, Edward
• Granted Patent: US 7,203,111 B2
• Time in Patent Office: Days
• US Class Current: 365/203
• CPC Class Codes: G11C 7/12 Bit line control circuits, e.g. drivers, boosters, pull-up circuits, pull-down circuits, precharging circuits, equalising circuits, for bit lines

Abstract

An embodiment includes a first semiconductor element coupled between a precharge signal and a node, the first semiconductor element to allow current to flow from the precharge signal to the node when a positive voltage is present on the precharge signal, and a switching device coupled between the node and a voltage signal, the switching device to allow current flow between the node and the voltage signal when an enable signal is asserted.

Claims

1. An apparatus, comprising:

a first semiconductor element coupled between a precharge signal and a node, the first semiconductor element to allow current to flow from the precharge signal to the node when a positive voltage is present on the precharge signal; and

a switching device coupled between the node and a voltage signal, the switching device to allow current flow between the node and the voltage signal when an enable signal is asserted.

2. The apparatus of claim 1, the first semiconductor element comprising a diode.

3. The apparatus of claim 2, the switching device comprising a transistor including a gate, the enable signal coupled to the gate.

4. The apparatus of claim 3, the diode including an anode and a cathode, the anode coupled to the precharge signal and the cathode coupled to the node.

5. The apparatus of claim 4, the node coupled to a MEMS device.

6. The apparatus of claim 5, further comprising a capacitor coupled between the node and ground.

7. The apparatus of claim 6, the precharge signal comprising a row precharge signal and the voltage signal comprising a column voltage signal.

22. The apparatus of claim 5, further comprising means for holding charge coupled between the node and ground.

23. The apparatus of claim 6, the precharge signal comprising a row precharge signal and the voltage signal comprising a column voltage signal.

8. A method, comprising:

applying a row precharge voltage to a node;

setting a column voltage; and

asserting a row enable signal to a switching device coupled between the node and the column voltage to cause the node voltage to approximately match the column voltage.

9. The method of claim 8, wherein applying a row precharge voltage to a node includes applying a row precharge voltage to an anode of a diode.

10. The method of claim 9, wherein applying a row precharge voltage to a node further includes coupling a cathode of the diode to the node.

11. The method of claim 10, wherein applying a row precharge voltage to a node further includes applying a row precharge voltage to a MEMS device coupled to the node.

12. A method, comprising:

applying a row precharge voltage to a node;

setting a column voltage; and

pulsing a row enable signal to a switching device coupled between the node and the column voltage to cause the node voltage to be lowered to a desired level.

13. The method of claim 12, wherein pulsing a row enable signal includes modulating a row enable signal pulse width to cause the node voltage to be lowered to the desired level.

14. The method of claim 12, wherein pulsing a row enable signal includes modulating a row enable signal pulse magnitude to cause the node voltage to be lowered to the desired level.

15. The method of claim 12, wherein pulsing a row enable signal includes periodically pulsing the row enable signal following an assertion of the row precharge signal.

16. The method of claim 12, wherein setting a column voltage includes setting the column voltage to a voltage less that 1V.

17. The method of claim 12, wherein applying a row precharge voltage to a node includes applying a row precharge voltage to an anode of a diode.

18. The method of claim 17, wherein applying a row precharge voltage to a node further includes coupling a cathode of the diode to the node.

19. The method of claim 18, wherein applying a row precharge voltage to a node further includes applying a row precharge voltage to a MEMS device coupled to the node.

20. An apparatus, comprising:

means for allowing current to flow from a precharge signal to a node when a positive voltage is present on the precharge signal; and

means for allowing current to flow between the node and a voltage signal when an enable signal is asserted.

21. The apparatus of claim 20, the node coupled to a MEMS device.

24. An apparatus, comprising:

one or more semiconductor devices adapted to provide an input node signal to a MEMS device, as follows;

applying a row precharge voltage to an input node;

setting a column voltage; and

asserting a row enable signal to a switching device coupled between the input node and the column voltage to cause the input node voltage to approximately match the column voltage.

25. The apparatus of claim 24, wherein applying a row precharge voltage to an input node includes applying a row precharge voltage to an anode of a diode.

26. The apparatus of claim 25, wherein applying a row precharge voltage to an input node further includes coupling a cathode of the diode to the input node.

27. The apparatus of claim 26, wherein applying a row precharge voltage to an input node further includes applying a row precharge voltage to the MEMS device coupled to the input node.

28. An apparatus comprising one or more semiconductor devices adapted to provide an input node signal to a MEMS device, as follows:

applying a row precharge voltage to an input node;

setting a column voltage; and

pulsing a row enable signal to a switching device coupled between the input node and the column voltage to cause the input node voltage to be lowered to a desired level.

29. The apparatus of claim 28, wherein pulsing a row enable signal includes modulating a row enable signal pulse width to cause the input node voltage to be lowered to the desired level.

30. The apparatus of claim 28, wherein pulsing a row enable signal includes modulating a row enable signal pulse magnitude to cause the input node voltage to be lowered to the desired level.

31. The apparatus of claim 28, wherein pulsing a row enable signal includes periodically pulsing the row enable signal following an assertion of the row precharge signal.

32. The apparatus of claim 28, wherein setting a column voltage includes setting the column voltage to a voltage less that 1V.

33. The apparatus of claim 28, wherein applying a row precharge voltage to an input node includes applying a row precharge voltage to an anode of a diode.

34. The apparatus of claim 33, wherein applying a row precharge voltage to an input node further includes coupling a cathode of the diode to the input node.

35. The apparatus of claim 34, wherein applying a row precharge voltage to an input node further includes applying a row precharge voltage to a MEMS device coupled to the input node.

36. A method, comprising:

coupling a diode between a row precharge signal and an input node; and

coupling a switching device between the input node and a column voltage signal.

37. The method of claim 36, wherein coupling a switching device between the input node and the column voltage signal includes coupling a transistor between the input node and the column voltage signal.

38. The method of claim 37, further comprising coupling a row enable signal to a gate terminal of the transistor.

39. The method of claim 38, further comprising coupling the input node to a MEMS device.

40. An apparatus, comprising:

a gated diode coupled between a diode bias reference signal and a node, the gated diode to allow current to flow from the diode bias reference signal to the node when a diode gate signal is asserted; and

a switching device coupled between the node and a voltage signal, the switching device to allow current flow between the node and the voltage signal when a charge release signal is asserted.

41. The apparatus of claim 40, the switching device comprising a transistor including a gate, the charge release signal coupled to the gate.

42. The apparatus of claim 41, the node coupled to a MEMS device.

43. The apparatus of claim 42, further comprising a capacitor coupled between the node and ground.

44. The apparatus of claim 43, the voltage signal coupled to ground.